Snow thins on Arctic sea ice

Historic data from NASA aircraft, ice buoys and former Soviet ice floe bases have been used to establish that snow has thinned on Arctic sea ice since the 1950s

University of Washington researchers used handwritten logs that recorded snow depths taken with crude measuring sticks. Contemporary researchers use an automated probe similar to a ski pole to verify airborne measurements.

‘When you stab it into the ground it records the distance between the magnet and the end of the probe,’ said Melinda Webster, a researcher from the University of Washington. ‘You can take a lot of measurements very quickly. It’s a pretty big difference from the Soviet field stations.’

The study found that western Arctic snow cover has decreased by a third, and snowpack in the Beaufort and Chikchi seas is less than half as thick as the average readings taken in previous years. A later surface freeze, meaning the year’s heaviest snow fall occurs over open seas, is thought to be responsible. Thin snow cover impacts Arctic animals that build dens and the microscopic plants that grow under the sea ice. The project was part of NASA’s Operation IceBridge programme, which uses aircraft to track changes in Arctic ice. A NASA satellite to monitor sea ice is set for launch in 2017.